Hydraulic system and pump means therefor



y 2, 1957 c. E. ADAMS ETAL 2,797,551

' HYDRAULIC SYSTEM AND PUMP MEANS THEREFOR Filed May 17, 1952 2 Sheets-Sheet l 4 F I ll: 1 V I; r m a 4 q- (\l a o:

I VINVENTORS GEGIL E ADAMS y JOHN R. ENGLISH w-OMMWAMF y 957 c. E. ADAMS ETAL 2,797,551

HYDRAULIC SYSTEM AND PUMP MEANS THEREFOR Filed May 17, 1952 2 She'ets-Sheet 2 INVENTORS GEO/L E. ADAMS y JOHN R. ENGLISH @MKW M United States Patent Ofiicc 2,797,551 Patented July 2, 1957 HYDRAULIC SYSTEM AND PUMP MEANS THEREFOR Cecil E. Adams and John R. English, Columbus, Ohio, assignors, by mesne assignments, to American Brake Shoe Company, New York, N. Y., a corporation of Delaware Application May 17, 1952, Serial No. 288,476

Claims. (Cl. 60-97) This invention relates to hydraulics and is particularly directed to a hydraulic system and apparatus for synchronizing the operations of reversible fluid motors.

One of the objects is to provide a simple apparatus whereby the operations of a plurality of reversible fluid motors may be automatically synchronized.

Another object is to provide hydraulic pumping mechanism, including a plurality of outlets from which substantially equal volumes of hydraulic fluid will be discharged and providing means for conducting the fluid from the outlets of the pumping mechanism to a plurality of reversible fluid motors to cause their independent but substantially simultaneous operation until resistance of a predetermined amount is encountered, the mechanism including an automatic valve which, when the predetermined resistance is encountered by any of the fluid motors, will operate to combine the exhausts from the outlets of the pumping mechanism whereby the full outlet pressure of the pumping mechanism will be applied equally to all of the fluid motors.

A further object of the invention is to provide ,a vane pump having a pair of substantially balanced pumping sections with separate outlet ports and a fluid pressure responsive valve mechanism for connecting the outlet ports when a predetermined pressure is developed in either of such ports. I

A still further object of the invention is to provide conduit means for connecting the outlets of the pump, mentioned in the preceding paragraph, with a pair of reversible fluid motors of the reciprocating piston type, directional control valves being provided in such conduits to cause the pistons of the motors to move in predetermined directions, to conduits being connected with the automatic valve means so that fluid delivered from the pump outlets will be conducted to the power cylinders independently until a predetermined pressure is built up in. one or the other or both conduits at which time the automatic valve will operate to connect the conduits whereby the total pressure of the pump will be maintained in both outlets and be applied to both pistons.

Further objects and advantages of the present invention will be apparent from the following description, reference being had to the accompanying drawings wherein a preferred form of embodiment of the invention is clearly shown.

In the drawings:

Fig. 1 is a diagrammatic view of a circuit embodying the present invention, parts of the devices incorporated in the circuit being shown in section. V

Fig. 2 is a longitudinal sectional view taken through a pump formed in accordance with the present invention, this pump having an automatic valve incorporated therein.

Referring more particularly to the drawings, the numeral 20 designates the hydraulic system in its entirety. This system includes a reservoir 21, a pump 22, an automatic valve 23, and a pair of reversible fluid motors 24,

these motors being disclosed as power cylinders with reciprocating pistons 25 and rams 26 to be operated thereby. The numeral 27 designates direction control valves, one being provided for each fluid motor 24. The pump 22 is of the vane type, being similar to the one shown in our copending application Serial No. 226,844, filed May 17, 1951, now Patent No. 2,762.312, issued September 11, 1956.

This pump includes a body 28 which forms a pumping chamber 30 having open ends, these ends being closed by heads 31 and 32. The head 31 constitutes the inlet end head of the pump and is provided with an inlet port 33. This head includes an annular chamber 34, a bore 35 extending through this annular chamber and receiving bearings 36 and 37 for the rotatable reception of a shaft 38. One end of the shaft projects from the head 31 for the reception of means for connecting the shaft to a prime mover, not shown. The other end of this shaft is splined as at 40 for connection with a rotor body 41 which is disposed in the chamber 30.

This rotor body is provided at circumferentially spaced intervals with slots 42 for receiving radially extending vanes 43, the vanes and the body 41 having registering recesses for the reception of springs 44 employed to urge the vanes in an outward direction into contact with the inner surface of .a cam ring 45. This cam ring has a substantially oval shaped central opening which receiver the rotor 41, the ends of the oval providing pumping chambers 47 and 48. These pumping chambers are diametrically opposed and, at one end of each chamber, are connected with the annular chamber 34. Since this chamber is connected with the inlet port 33, fluid may flow from the inlet port to the chamber and from the latter into the pumping chambers. The opposite ends of the pumping chambers are connected with outlet ports 50 formed in the head 32. When the shaft 38 is revolved in a clockwise direction, as viewed in Fig. 1, the vanes 43 will transfer fluid from the inlet ports to the outlet ports 50. The heads 31 and 32 are provided with pass-ages to conduct fluid to the inner ends of the vanes 43 so that fluid pressures at the inner and outer ends of these vanes willbe equalized. From the ports 50, fluid conductors 51 and 52 extend to the inlet ports of the directional con trol valves 27. These conductors 51 and 52 communicate with ports 53 and 54, respectively, of the automatic valve mechanism designated generally by the numeral 23.

In the form of the invention illustrated in the drawings, this valve is incorporated in the head 32 of the pump 22. The ports 53fland 54 constitute spaced annular grooves which extend around a central bore 55. This bore is provided for the reception of a valve piston 56 which has an external annular groove 57 formed therein. The piston 56 is normally urged toward one end of the bore 55 by a spring 58 and, when it is disposed at suchend of the bore, the groove 57 communicates only with the groove 54. The piston 56 has a passage 60, extending from one end to the other so that fluid may flow between the ends to permit the movement of the piston without undue resistance. The piston is also provided with a central piston chamber 61 in which a pair of plungers 62 and 63 are disposed in end to end relationship. The piston body 56 is also provided with a pair of ports 64 and 65, the former leading from the groove 57 to the intermediate portion of the pisto the reservoir through line 66. The valve piston 56 will occupy the position shown in Fig.2 at this time. When it is desired to cause the operation of the motors 24, the valves 27 will be actuated to connect lines 67 with lines 51 and 52. The discharge of the pump 22 through the outlet ports 50 will then be conducted to the inner ends of the power cylinders 24. The outer ends of these cylinders will be connected through lines 68 and valves 27 with line 66 leading to the reservoir 21. The operation of pump 22 will then cause the pistons to moveoutwardly of the cylinders 24. Since the discharge from the pumping sections of the pump 22 will be substantially equal and the power cylinders 24 are equal in size, the pistons 25 will move'at substantially the same rate. When either ram 26 meets an obstruction which offers a resistance of predetermined amount, the pressure in the respective line leading to the motor operating that ram'will increase. This pressure will be conducted through the port 64 and 65 and will exert a force on the piston valve 56 causing this valve to move in opposition to the spring58 until the groove 57 establishes communication between the grooves 53 and 54. At this time the outlets of the pump 22 will be connected and the full pressure developed by the pump will obtain in both lines 51 and 52. This pressure will also obtain in the power cylinders 24 causing the pistons of these power cylinders 'to exert equal forces on the rams 26, the latter transferring the forces to the work engaged thereby. When the directional control valves are operated to reverse the connections offthe lines 51 and 52 with the fluid motors 24, the pistons and rams will be retracted. When this reversal is effected, the pressure in the lines 51 and 52 will immediately fall permitting spring 58 to return piston valve 56 to its normal position wherein lines 51 and 52 are disconnected from one another.

A drain line 70 extends from the end of the chamber 55 opposite the spring to conduct seepage fluid to the reservoir 21. The pressure at which valve 56 establishes communication between the outlet lines 51-and 52 may be varied through the adjustment of a screw 71 threadedly received bya cover 72 for the end of the head 32. This cover closes the end of the bore 55. When the screw 71 is adjusted, an adapter 73 is urged inwardly or outwardly'to load or unload the spring 58.

It should be obvious that, while a single pumping mechanism has been illustrated, the mechanism is designed and constructed to functionas two substantially duplicate pumping devices and could, therefore, be readily replaced by two or more pumps without affecting the principles of the invention.

It should also be obvious that, while a vane pump has been provided, other types of pumps could be employed also without affecting the principles of operation of the hydraulic system. The 'vane pump has been selected for illustration because of its adaptability to the invention.

While the form of embodiment of the present invention as herein disclosed constitutes apreferred form, it is to be understood that other forms might be adopted, all coming within the scope of the claims which'follow:

We claim:

1. A hydraulic system comprising a plurality of independent sources of'fluid pressure; a plurality of reversible fluid motors; a directional control valve between each source of pressure and eachmotor; and an automatic valve mechanism responsiveto predetermined pressures in any of said sources to establish a fluidpressureconnection between all of said sources.

2. A hydraulic system comprising a plurality of independent substantially equal sources of fluid pressure; a plurality of substantially identical reversible fluid motors; a directional control valve between each source of pressure and each motor; and. an automatic valvemechanism between said directional control valves and said pressure sources, said valve mechanism being responsive to predetermined pressuresin anyof said sources to establish a fluid pressure connection between all of said sources.

3. Al1ydraulic system'comprising aplurality of independent substantially equal fluid pressure pumps; a single driving member for simultaneously operating said pumps; a plurality of reversible fluid motors; a directional control valve between each source of pressure and each motor; and a pressure responsive valve between said directional control valves and said pumps; said valve being actuated by predetermined pressure generated by any of said pumps to establish a fluid pressure connection between all of said 4. A hydraulic system comprisingpump means having a pair of independent outlets; a pair of reversible fluid motors; a directional control valve for each of said motors; fluid conducting means connecting one outlet with one directional controland the other outlet with the other directional control; and valve means responsive to pressure in either outlet to establish communication between said outlets.

5. A hydraulic system comprising a fluid pump having a pair of pumping sections with separate outlets; a pair of reversible fluid motors; a directional control valve for each of said motors; a fluid conductor connecting one of said outlets with one directional control valve and the other outlet with the other directional control valve; and valve means responsive to a. predetermined pressure in either fluid conductor to establish a connection between said conductors.

6. A hydraulic system comprising a pump means having separate pumping sections of substantially equal capacity; a reversible fluid motor connected with each pumping section; a directional control valve between each pumping section and motor and pressure responsive valve means for establishing communication between said pump ing sections when the pressure in either section increases beyond a predetermined amount.

7. A fluid pump having a pair of separate pumping sections, of equal capacity each having an outlet, a spool valve connected between said outlets; resilient means normally tending tomaintain said valve in a closed position; and passage means exposing said valve to pressures in said outlets, said valve being moved by predetermined pressure in either of said outlets to a position to establish communication between said outlets.

8. A fluid pressure energy translating device comprising'a body with a substantially oval rotorchamber; a substantially cylindrical rotor disposed for rotation in said chamber, said rotor having radial slots formed therein, the'ends of said oval'chamber providing substantially balanced working chamber sections, said body having fluid ports at the-ends of said chamber sections; vane means in the slots in said rotor, said vane means traversing said working chamber sections upon rotation of said rotor; and valve means connected bet-weenand responsive to predetermined fluid pressures in either of corresponding fluid ports to establish communication between such corresponding ports.

9. A fluid pressure energy translating device comprising a body with balanced working chambers having separate corresponding fluid inlet and outlet ports; vane means traversing said working chambers during the operation of said device; a valve means havinga body forming a valve chamber with spaced ports connected with the separate outlet ports of said working chambers; spool means disposed for movement in said valve chamber; means normally urging said spool means toward aposition to prevent communication between the ports in said valve chamber; and piston means responsive to predetermined pressures in either of said outlets to move said spool means in opposition to said urging means to a position to establish communication between the ports in said valve chamber.

10. A fluid pressure energy translating device comprising a body with balanced working chambers having separate corresponding fluid inlet and outlet ports; vane means traversing said working chambers during the operation of said device; a valve means having a body forming a valve chamber with spaced ports connected with the separate outlet ports of said working chambers; spool means disposed for movement in said valve chamber; means normally urging said spool means toward a position to prevent communication between the ports in said valve cham- 6 her; a socket in said spool means; and a pair of pistons disposed end to end in said socket, the inner end of said socket being in communication with one of the ports in said valve chamber and the space between said spools being in communication with the other of the ports in said 10 valve chamber.

1,049,894 Merrill Jan. 7, 1913 15 6 Kinsella May 27, 1930 Vickers Oct. 22, 1940 Crosby Jan. 2, 1945 Tweedale Nov. 26, 1946 Holley Apr. 27, 1948 Robinson et a1. Dec. 5, 1950 Harrington et al Mar. 13, 1951 Herbelleau Jan. 15, 1952 Carlson June 30, 1953 Schanzlin Oct. 13, 1953 

